JP6420401B2 - Transparent member with diffuse reflection - Google Patents

Description

  The present invention relates to a transparent layered member having diffuse reflection characteristics.

  The layered member may be hard or soft. In particular it can be used for all known glazing applications such as, for example, cars, buildings, street fixtures, interior fixtures, display screens, for example glazing constructed on the basis of glass or polymer materials. It may also be a soft film based on a polymer material that can be added to the surface so as to preserve its transmission properties, particularly giving it diffuse reflection properties.

  Known glazing includes standard transparent glazing and translucent glazing, but transparent glazing results in specular transmission and specular reflection of radiation incident on the glazing, and translucent glazing is incident on the glazing Provides diffuse transmission and diffuse reflection of radiation.

  Normally, when radiation incident on a glazing at a predetermined angle of incidence is reflected in multiple directions by glazing, the reflection due to glazing is said to be diffuse. When radiation incident on a glazing at a predetermined angle of incidence is reflected by glazing at a reflection angle equal to the angle of incidence, the reflection due to glazing is said to be specular. Similarly, when radiation incident on a glazing at a predetermined angle of incidence is transmitted at a transmission angle equal to the angle of incidence by glazing, the transmission that has passed through the glazing is said to be specular.

  One disadvantage of standard transparent glazing is that it is transparent and produces a mirror-like reflection, which is desirable in certain applications. Therefore, when glazing is used in building windows or display screens, it is desirable to limit the presence of reflections that obstruct visibility throughout the glazing. The sharp reflection of glazing can also create a blinding risk as a result from a safety point of view when, for example, an automobile headlight is reflected on a glass facade of a building. This problem is very pronounced with respect to airport glass facades. In fact, when a pilot approaches the terminal, it is essential to eliminate any dangers regarding the glare of the pilot. Furthermore, translucent glazing has the advantage of not producing a clear reflection, however, it is impossible to obtain a clear view through the glazing.

  The present invention more particularly proposes a layered member that has a clear view through the member, limits the mirror-like reflection of the member, and at the same time allows to promote diffuse reflection of the member. It is intended to overcome the shortcomings.

For this purpose, one subject of the present invention is a transparent layered member having two flat outer major surfaces,
Two outer layers each comprising one of the two outer major surfaces of the layered member and composed of a dielectric material having substantially the same refractive index, and a central layer interposed between the outer layers, Formed by a single layer that is a dielectric layer or metal layer having a different refractive index than the outer layer, or formed by stacking layers comprising at least one dielectric layer or metal layer having a different refractive index from the outer layer Each contact surface between two adjacent layers of a layered member comprising a central layer, one being a dielectric layer and the other being a metal layer, or two dielectric layers having different refractive indices is And the remaining textured contact surface between two adjacent layers, one of which is a dielectric layer and the other is a metal layer or two dielectric layers having different refractive indices Parallel to It is a layered member characterized by this.

  Within the scope of the invention, on the one hand, differences occur between the metal layers, but the difference in the value of the refractive index with respect thereto is not significant, whereas on the other hand, the dielectric layer has a refractive index of the outer layer. The difference in refractive index with respect to must be taken into account. The expression “dielectric material or layer” is understood to mean a material or layer with a low electrical conductivity of 100 S / m or less.

  Each outer layer of the layered member can be formed of a stack of layers as long as the various constituent layers of the outer layer are all composed of a dielectric material having substantially the same refractive index.

  In the sense of the present invention, when the absolute value of the difference in their refractive index at 550 nm is 0.15 or less, the two dielectric materials have substantially the same refractive index or their refractive index. Are substantially equal. Preferably, the absolute value of the difference in refractive index at 550 nm between the constituent materials of the two outer layers of the layered member is less than 0.05, more preferably less than 0.015.

  In the sense of the present invention, the two dielectric layers have different refractive indices if the absolute value of their refractive index difference at 550 nm is strictly greater than 0.15.

  In the sense of the present invention, the contact surface between two adjacent layers is the interface between the two adjacent layers.

  Within the scope of the present invention, the following definitions are used.

  A transparent member is a member that is transparent to radiation at least in the wavelength range used for the targeted application of the member. As an example, when used as glazing for buildings or automobiles, the member is transparent at least in the visible wavelength range.

  A flat surface is a surface whose surface irregularities have dimensions that are shorter than the wavelength of radiation incident on the surfaces, so that the radiation is not refracted by these surface irregularities. Incident radiation is consequently transmitted and reflected by the surface in a specular / specular transmission manner.

  An uneven surface is a surface whose surface properties are changing on a scale greater than the wavelength of radiation incident on the surface. Incident radiation is consequently transmitted and reflected by the surface in a diffuse manner.

  As a result of the present invention, regular transmission and diffuse reflection of radiation incident on the layered member are obtained. Regular transmission ensures a clear view through the layered member. Diffuse reflection makes it possible to avoid the risk of sharp reflection and glare by the layered member.

  The diffuse reflection of a layered member is such that the respective contact surface between two adjacent layers, one of which is a dielectric layer and the other is a metal layer, or two dielectric layers having different refractive indices. This is due to the fact that there are irregularities. Thus, when radiation incident on the layered member reaches such a contact surface, it is reflected by the metal layer or because of the difference in refractive index between the two dielectric layers, and the contact surface is uneven. Because there is, the reflection diffuses.

  Regular transmission is the fact that the two outer layers of the layered member have a flat outer major surface and are composed of materials having substantially the same refractive index, as well as one being a dielectric layer and the other being Each uneven contact surface between two adjacent layers of a layered member that is a metal layer or two dielectric layers having different refractive indices, one is a dielectric layer and the other is Due to the fact that it is a metal layer or parallel to the other of the uneven contact surfaces between two adjacent layers that are two dielectric layers with different refractive indices.

  The flat outer surface of the layered member allows specular transmission of radiation at each atmosphere / outer layer interface, i.e., radiation enters the outer layer from the atmosphere or radiation from the outer layer without changing the direction of radiation. Allows you to get out into the atmosphere.

  The parallelism of the uneven contact surface is a dielectric layer having a refractive index different from that of the outer layer, or each constituent layer of the central layer which is a metal layer is in contact with the contact surface of the outer layer and the central layer. Means a constant thickness measured at right angles. This thickness homogeneity may be full over the entire unevenness or local over the unevenness. In particular, when there is a change in the slope of the unevenness, the thickness between two consecutive uneven contact surfaces can vary from part to part depending on the slope of the unevenness, however, the uneven contact surfaces are always Maintaining parallelism. This case is particularly relevant for layers deposited by sputtering, where the thickness of the layers is proportionally thinner as the slope of the irregularities increases. Therefore, in the unevenness of each part having a predetermined inclination, the thickness of the layer is locally maintained constant, but the thickness of the layer is different from the unevenness of the first part having the first inclination, The unevenness of the second part having a second slope different from the first slope is different.

  Advantageously, each component layer of the central layer is a layer deposited by sputtering in order to obtain a parallel contact surface with irregularities in the layered member. Indeed, sputtering, particularly magnetron sputtering, ensures that the surfaces separating the layers are parallel to each other, but other deposition techniques such as evaporating or chemical vapor deposition (CVD), or sol- It is not ensured in the case of the gel method. Nevertheless, the parallelism of the uneven contact surface in the layered member is essential for obtaining specular transmission through the member.

  Radiation incident on the first outer layer of the layered member passes through this first outer layer without changing its direction. Due to the difference in dielectric or metallic properties or the difference in refractive index between the first outer layer and at least one of the central layers, the radiation is refracted in the central layer. On the one hand, the uneven contact surface between two adjacent layers of a layered member, one of which is a dielectric layer and the other is a metal layer, or two dielectric layers having different refractive indices is , Since the second outer layer has substantially the same refractive index as the first outer layer, according to Snell-Cartesian law of refraction, The angle of refraction of radiation in the two outer layers is equal to the angle of incidence of radiation in the central layer starting from the first outer layer.

  Thus, radiation emerges from the second outer layer of the layered member along a direction that is the same as the direction of incidence on the first outer layer of the member. Therefore, the transmission of radiation by the layered member is regular transmission.

  According to one aspect of the invention, the diffuse reflection properties of the layered member are utilized to reflect most of the radiation in multiple directions on the side on which the radiation is incident. While obtaining this high diffuse reflection, at the same time it has a clear field of view through the layered member, i.e. the layered member is translucent due to the specular transmission properties of the layered member. Such a transparent layered member with high diffuse reflection fulfills applications for display screens or projection screens, for example.

  In particular, such a layered member with high diffuse reflection can be used in a head-up display (HUD) system. In a known manner, especially HUD systems that are used not only in airplane cockpits, trains, but also in personal cars (passenger cars, trucks, etc.) today, glazing reflected towards the driver or passenger, in general It is possible to display the information projected on the windshield of the car. These systems allow the driver to inform the driver without having to look away from the vehicle's forward view, which allows for a significant increase in safety. The driver recognizes that the virtual image is located at a certain distance behind the glazing.

  According to one aspect of the invention, the layered member is incorporated into the HUD system as a glazing onto which information is projected. According to another aspect of the invention, the layered member is a glazing of the HUD system, in particular a soft film added on the main surface of the windshield, and information is projected on the glazing on the soft film side. In these two cases, a high diffusive reflection that allows a good visualization of the virtual image occurs at the first uneven contact surface where radiation encounters in the layered member, while providing a clear view through glazing. Regular transmission through the glazing to be secured is maintained.

  Note that in prior art HUD systems, a virtual image is obtained by projecting information onto a glazing (especially a windshield) having a laminate structure formed by two glass sheets and a plastic intermediate layer. That. One drawback of these existing systems is that, as a result, the driver has a double image: a first image reflected by the inwardly facing glazing surface in the car and a second by reflection of the outer surface of the glazing. To see the images, these two images are slightly offset from each other. This deviation may interfere with the viewing of information.

  The present invention can overcome this problem. In practice, when the layered member is incorporated into a HUD system as a glazing receiving radiation from the projection light source or added to the main surface of the glazing, the first uneven contact encountered by the radiation in the layered member The diffuse reflection at the surface can be significantly higher than that of the outer surface in contact with the atmosphere. Therefore, double reflection is suppressed by promoting reflection by the contact surface with the first unevenness of the layered member.

  According to one advantageous feature, the absolute value of the refractive index difference at 550 nm between the outer layer on the one hand and the at least one dielectric layer on the other hand on the other hand is 0.3 or more, preferably 0.5 or more, More preferably, it is 0.8 or more. This relatively large difference in refractive index occurs at least one uneven contact surface in the layered member. This makes it possible to promote the reflection of radiation on the uneven contact surface, that is, the diffuse reflection of radiation by the layered member.

  According to one aspect of the present invention, at least one of the two outer layers of the layered member is a transparent substrate, one of the main surfaces of the transparent substrate is roughened, and the other main surface Is flat.

  The transparent substrate can in particular consist of a transparent polymer, transparent glass or transparent ceramic. If the transparent substrate is composed of a polymer, it may be hard or soft.

  The unevenness of one main surface of the transparent base material is obtained by any known unevenness forming method, for example, by embossing the surface of the base material by preheating the surface to a temperature at which the surface of the base material can be deformed, In particular by rolling with a roll having irregularities complementary to the irregularities formed on the surface thereof; by polishing with abrasive particles or abrasive surfaces, in particular by sandblasting; by chemical treatment, in particular It can be obtained by acid treatment in the case of glass substrates; by molding, in particular by injection molding in the case of substrates made from thermoplastic polymers; by engraving.

  Examples of suitable polymers for transparent substrates include, in particular, polyesters such as, for example, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN); for example polymethyl methacrylate Polyacrylate such as (PMMA); Polycarbonate; Polyurethane; Polyamide; Polyimide; ECTFE), fluoropolymers such as fluorinated ethylene-propylene (FEP) copolymer; for example, photocurable and / or photopolymerizable such as thiolene resin, polyurethane resin, urethane-acrylic resin, polyester-acrylic resin Butter, and the like.

  Examples of glass substrates that are already uneven and can be used as they are as the outer layer of a layered member are sold by Saint-Gobain Glass, Inc., which has unevenness obtained by sandblasting or acid treatment on one of their main surfaces Glass substrate SATINOVO (registered trademark); glass substrate ALBARINO (registered trademark) S, P or G or glass sold by Saint-Gobain Glass, Inc., which has irregularities obtained by rolling on one of its main surfaces Examples include the substrate MASTERGLASS (registered trademark).

  When each of the two outer layers of the layered member is formed by a transparent substrate having one of its main surfaces having irregularities and the other main surface being flat, the two transparent substrates are It has complementary irregularities.

  In one embodiment, the central layer of the layered member is formed by a layer of dielectric material having a different refractive index than the outer layer, and the outer layer is assembled by the central layer.

In another embodiment, the central layer of the layered member is a dielectric material having a high refractive index different from the refractive index of the outer layer, such as Si ₃ N ₄ , SnO ₂ , ZnO, AlN, NbO, NbN, TiO _2, etc. Or a dielectric material having a low refractive index unlike the refractive index of the outer layer, for example, at least one thin layer made of SiO ₂ , Al ₂ O ₃ , MgF ₂ , AlF ₃ or the like. The central layer of the layered member may also include its at least one thin metal layer, particularly a thin layer of silver, gold, titanium, niobium, silicon, aluminum, nickel-chromium (NiCr) alloy, stainless steel, or alloys thereof. it can. In the sense of the present invention, a thin layer is a layer having a thickness of less than 1 micrometer.

  Advantageously, the composition of the central layer of the layered member can also be adjusted to give the layered member additional properties such as solar control and / or low emissivity type thermal properties. Thus, in one embodiment, the central layer of the layered member comprises an alternating arrangement of n metal functional layers, in particular functional layers based on silver or a metal alloy containing silver, and (n + 1) antireflective coatings. A stack of transparent thin layers comprising (n ≧ 1), each functional metal layer being deposited between two anti-reflective coatings.

  As is known, such stacks with functional metal layers have reflective properties in the solar radiation range and / or in the long wavelength infrared radiation range. In such a stack, the functional metal layer (s) substantially determines the thermal properties, while the anti-reflective coating surrounding them acts coherently on the optical appearance. In practice, the metal functional layers make it possible to obtain the desired thermal properties even with a geometric thickness as thin as 10 nm of each functional metal layer, however, they are within the visible wavelength range. Strongly block the passage of radiation. Therefore, antireflection coatings on both sides of each functional metal layer are necessary to ensure good light transmission in the visible range. In practice, it is an overall stack of optically optimized central layers containing a thin metal layer and an anti-reflective coating. Advantageously, optical optimization may be performed on the overall stack of layered members, i.e. including the outer layers located on either side of the central layer.

  As a result, the obtained layered member has optical characteristics, i.e., regular transmission and diffuse reflection characteristics of radiation incident on the layered member, and thermal characteristics, i.e., solar control and / or low emissivity characteristics. Such layered members can be used for solar shading and / or thermal glazing of buildings or automobiles.

に等しい。 According to one aspect of the present invention, between two adjacent layers of a layered member, one of which is a dielectric layer and the other is a metal layer, or two dielectric layers having different refractive indices. The unevenness of each contact surface is formed by a plurality of features that are recessed or protruding relative to the general plane of the contact surface. Preferably, each contact surface feature between two adjacent layers of a layered member, one being a dielectric layer and the other being a metal layer, or two dielectric layers having different refractive indices. The average height is from 1 micrometer to 1 millimeter. In the sense of the present invention, the average height of the contact surface features is defined as the arithmetic average of the absolute values of the distances y _i measured between the contact surface peak and the general surface for each feature of the contact surface,

be equivalent to.

  Features of irregularities on the respective contact surfaces between two adjacent layers of a layered member, one being a dielectric layer and the other being a metal layer, or two dielectric layers having different refractive indices Can be randomly assigned on the contact surface. As a variant, the respective contact surface between two adjacent layers of a layered member, one of which is a dielectric layer and the other is a metal layer, or two dielectric layers having different refractive indices. Concavity and convexity features can be periodically assigned on the contact surface. These features can in particular be cones, pyramids, grooves, ribs, wavelets.

  According to one aspect of the present invention, with respect to each layer of the central layer surrounded by a layer having a different dielectric or metallic property, or a refractive index different from each layer of the central layer, different from each layer of the central layer The thickness of this layer, measured perpendicular to its contact surface with the adjacent layer, is small compared to the average height of each feature of the contact surface with the adjacent layer. Such a small thickness increases the probability that the entrance interface of radiation into this layer and the exit interface of radiation from this layer are parallel, thus increasing the percentage of specular transmission of radiation through the layered member. It becomes possible. Advantageously, the thickness of each layer of the central layer inserted between two layers having different dielectric or metallic properties, or different refractive indices than the central layer, different from the central layer. The thickness is less than ¼ of the average height of the features of each contact surface with the adjacent layer when this thickness is measured perpendicular to the contact surface with the adjacent layer.

  Advantageously, the layered member comprises an anti-reflective coating on at least one of its flat outer major surfaces at the interface between the atmosphere and the outer layer constituent material forming the outer major surface. Thanks to the presence of this anti-reflection coating, the radiation incident on the side layer member of this outer main surface is the respective outer rather than flat outer surface of the layer member (corresponding to the diffuse reflection mode rather than the regular reflection mode). Reflected in a specular manner on an uneven contact surface. Therefore, diffuse reflection of radiation by the layered member is preferred over regular reflection.

  The anti-reflective coating provided on at least one of the outer major surfaces of the layered member can be of any type that can reduce the reflection of radiation at the interface between the atmosphere and the corresponding outer layer of the layered member. In particular, it has a refractive index between that of the atmosphere and that of the outer layer, for example a layer deposited on the surface of the outer layer by vacuum technology or a sol-gel type porous layer, or the outer layer is made of glass. If so, it may be the etched away surface portion of the outer glass layer obtained by an “etching” type acid treatment. As a variant, the anti-reflective coating can alternatively be formed by stacking thin layers with lower or higher refractive index that function as interference filters at the interface between the atmosphere and the outer layer, or the refractive index of the atmosphere and the outer layer. Can be formed by stacking thin layers with continuous or alternating refractive index gradients between.

  Advantageously, the flat outer major surfaces of the layered member are parallel to each other. This serves to limit the light dispersion of the radiation passing through the layered member, and thus helps to improve the clarity of the field of view through the layered member.

  In one embodiment of the present invention, of the two outer layers of the layered member, the first outer layer is a transparent substrate, one of the main surfaces of the transparent substrate is roughened, and the other main surface Is flat and the central layer is formed by a single layer that is a dielectric or metal layer having a different refractive index than the first outer layer deposited along the roughened main surface of the first outer layer. Or by stacking layers comprising at least one dielectric layer or metal layer having a different refractive index than the first outer layer continuously deposited along the roughened main surface of the first outer layer It is formed.

  The second outer layer is then substantially deposited with the first outer layer deposited on the roughened main surface of the central layer opposite the first outer layer, initially in a viscous state suitable for the molding operation. A layer of curable material having a refractive index equal to.

  According to one aspect of the invention, the second outer layer is constituted by a layer that is initially deposited in a viscous state, in particular a varnish type layer, so as to ensure a flattened surface of the layered member.

  According to another aspect of the invention, the second outer layer comprises a layer initially deposited in a viscous state and a counter substrate, said layer initially deposited in a viscous state and then a central layer. Ensure firm adhesion between the first outer layer provided with the counter substrate.

  The layer initially deposited in a viscous state may be a layer of photocrosslinkable and / or photopolymerizable material. Preferably, the photocrosslinkable and / or photopolymerizable material is liquid at ambient temperature and contains bubbles and other irregularities when it is irradiated and photocrosslinked and / or photopolymerized. Results in no transparent solids. It may in particular be a resin, such as those commonly used as adhesives, adhesives or surface coatings. In general, these resins are based on monomers / comonomer / prepolymers of the epoxy, epoxy silane, acrylate, methacrylate, acrylic acid or methacrylic acid type. For example, mention may be made of thiolene, polyurethane, urethane acrylate, and polyester acrylic resins. A photocrosslinkable aqueous gel such as a polyacrylamide gel may be used instead of the resin. Examples of photocrosslinkable and / or photopolymerizable resins that can be used in the present invention include products sold by Norland Optics under the trade name NOA (registered trademark) Norland Optical Adhesives, such as products NOA65 and NOA75. Can be mentioned.

As a variant, the second outer layer initially deposited in a viscous state may be a layer deposited by a sol-gel process, for example silica glass deposited by a sol-gel process. As is known, the precursor for silica glass sol-gel deposition is silicon alkoxide Si (OR) ₄ , which causes a hydrolysis-condensation type polymerization reaction in the presence of water. These polymerization reactions gradually increase the formation of condensed species, which results in colloidal silica particles that form a gel next to the sol. Drying and densifying these silicas at temperatures on the order of hundreds of degrees yields glasses with characteristics similar to those of conventional glasses. Because of their viscosity, colloidal solutions or gels are easily deposited on the rough main surface of the central layer opposite the first outer layer by following the rough surface. This deposition can be done in particular by dip coating, spin coating or braiding.

  According to one aspect of the present invention, the second outer layer is disposed on the roughened main surface of the central layer opposite to the first outer layer, and the roughened surface by compression and / or heating. A layer based on a polymeric material having a refractive index that is essentially equal to the first outer layer formed.

  This layer based on a polymer material can be a layer based in particular on polyvinyl butyral (PVB), ethylene / vinyl acetate (EVA), polyurethane (PU), polyethylene terephthalate (PET) or polyvinyl chloride (PVC). This layer, based on a polymeric material, serves as a lamination interlayer that provides a bond with a transparent substrate having a refractive index substantially equal to that of the first outer layer, and belongs to the second outer layer. Yes.

  The layered member may be soft glazing. As a variant, it may be a soft membrane. Such a flexible membrane is advantageously provided on the outer major surface, with an adhesive layer covered with a protective strip intended to be peeled off for adhesion of the membrane. A layered member in the form of a soft membrane can then be added to an existing surface, such as a glazing surface, by adhesion to impart diffuse reflection properties while maintaining normal transmission properties on the surface.

Another subject of the invention is
As the outer layer, a step of preparing two transparent base materials composed of dielectric materials having substantially the same refractive index, each transparent base material being flat with one main surface with unevenness A step of having the other main surface and the irregularities of the two transparent substrates are complementary to each other,
The central layer including at least one dielectric layer or metal layer having a refractive index different from the refractive index of the outer layer is provided with unevenness of two transparent substrates arranged so that the unevenness is parallel to each other. The method for producing the above-mentioned layered member is characterized by including a step of placing between the main surfaces.

Another method for manufacturing the layered member is as follows:
Preparing a transparent base material having one main surface with irregularities and the other main surface being flat as a first outer layer;
A step of depositing a central layer on a roughened main surface of the first outer layer, wherein the central layer is formed by a single layer that is a dielectric layer or a metal layer having a refractive index different from that of the first outer layer. In some cases, this is done by depositing a central layer along the roughened main surface, or the central layer comprises a layer comprising at least one dielectric or metal layer having a different refractive index than the first outer layer. If formed by stacking, a step performed by depositing a layer of the central layer continuously along the major surface with irregularities;
Forming a second outer layer on an uneven main surface of the central layer opposite to the first outer layer, wherein the first outer layer and the second outer layer have substantially the same refractive index. Consists of materials.

  According to one advantageous feature, the deposition of the central layer along the roughened main surface of the first outer layer or the continuous central layer deposition along the main surface is carried out by sputtering, in particular magnetron sputtering. Is called.

  According to an aspect of the invention, the second outer layer has substantially the same refractive index as the first outer layer on the roughened main surface of the central layer opposite to the first outer layer and is initially Formed by depositing a layer in a viscous state suitable for the molding operation. Thus, the second outer layer may be formed, for example, by a method involving the deposition of a layer of photocrosslinkable and / or photopolymerizable material that is initially in the form of a fluid and then irradiation of this layer, or a sol-gel method. Can do.

  According to another aspect of the present invention, the second outer layer is formed of a polymer material having substantially the same refractive index as that of the first outer layer on the roughened main surface of the central layer opposite to the first outer layer. A layer based on the polymer material is placed and then formed by subjecting this layer based on the polymer material to the roughened main surface of the central layer by at least compression and / or heating at the glass transition temperature of the polymer material.

  Another subject of the invention is a building facade, in particular an airport terminal facade, comprising at least one layered member as described above.

  Another subject of the present invention is a display screen or projection screen comprising the layered member described above. In particular, one subject of the present invention is the glazing of a head-up display system comprising the layered member described above.

  The final subject of the present invention is the use of the layered member described above as all or part of a glazing for a car, building, street fixture, interior fixture, display screen, head-up display system or projection screen.

  The features and advantages of the present invention will become apparent from the following description of several embodiments relating to layered members and the accompanying drawings, which are presented by way of example only.

It is a schematic sectional drawing of the layered member by one embodiment of this invention. It is an enlarged view of the detail I of FIG. 1 regarding the 1st deformation | transformation aspect of a layered member. It is the enlarged view of the detail I of FIG. 1 regarding the 2nd deformation | transformation aspect of a layered member. 2 is a schematic diagram showing steps of a first method for manufacturing the layered member of FIG. 1. 2 is a schematic diagram showing steps of a second method for producing the layered member of FIG. 1. FIG. 4 is a schematic diagram illustrating steps of a third method for manufacturing the layered member of FIG. 1. FIG. It is a schematic diagram showing the process of the 4th method for manufacturing the layered member of Drawing 1.

  For the sake of clarity, no strict consideration has been given to the relative thicknesses of the various layers of FIGS. The possible variation in the thickness of each constituent layer of the central layer depending on the slope of the irregularities is not shown in the figure, and this possible variation in thickness is the parallelism of the uneven contact surface It is understood that it does not affect. In practice, the uneven contact surfaces are parallel to each other for each predetermined slope of the unevenness.

  The laminar member 1 shown in FIG. 1 includes two outer layers 2 and 4, which are composed of a transparent dielectric material having substantially the same refractive index n2, n4. Each outer layer 2 or 4 has a flat main surface facing the outside of the layered member, 2A or 4A, respectively, and an uneven main surface facing the inside of the layered member, 2B or 4B, respectively.

  The flat outer surfaces 2A and 4A of the laminar member 1 allow the normal transmission of radiation on each surface 2A and 4A, ie the entrance of radiation into or out of the outer layer changes the direction of radiation. There is nothing to do.

  The irregularities of the inner surfaces 2B and 4B are complementary to each other. As can be clearly seen in FIG. 1, the uneven surfaces 2B and 4B are arranged so as to face each other, where in the three-dimensional arrangement they are strictly parallel. The layered member 1 also includes a central layer 3 inserted in contact between the uneven surfaces 2B and 4B.

In the modification shown in FIG. 2, the center layer 3 is a single layer and is made of a transparent material that is either a metal or a dielectric having a refractive index n3 different from that of the outer layers 2 and 4. In the variant of FIG. 3, the central layer 3 is formed by a transparent stack of several layers 3 ₁ , 3 ₂ ,..., 3 _k , where at least one of the layers 3 _{1 to} 3 _k is the outer layer 2. And a metal layer or a dielectric layer having a refractive index different from that of the above four. Preferably, at least each of the two layers 3 ₁ and 3 _k located at the end of the stack is a metal layer or dielectric having a refractive index n3 ₁ or n3 _k different from that of the outer layers 2 and 4.

1 to 3, S ₀ means the contact surface between the outer layer 2 and the center layer 3, and S ₁ means the contact surface between the center layer 3 and the outer layer 4. Further, in FIG. 3, S _{2 to} S _k continuously mean the inner contact surface of the central layer 3, starting from the contact surface closest to the plane S ₀ .

In the deformation mode shown in FIG. 2, the contact surface S ₀ between the outer layer 2 and the center layer 3 is formed due to the arrangement of the center layer 3 in contact between the uneven surfaces 2B and 4B parallel to each other. Are uneven and parallel to the contact surface S ₁ between the central layer 3 and the outer layer 4. In other words, the center layer 3, at least locally, a layer having irregularities having a constant thickness e3, measured at right angles to the contact surfaces S ₀ and S _1.

In the variant shown in FIG. 3, the contact surfaces S ₂ ,..., S _k between the two adjacent layers of the stack of components of the central layer 3 are uneven and centered with the outer layers 2, 4. It is strictly parallel to the contact surfaces S ₀ and S ₁ between the layers 3. Thus, the contact surfaces S ₀ , S ₁ ,... Between adjacent layers of the member 1 that are either layers of different properties, dielectric or metal, or are dielectric layers having different refractive indices. All of S _k are uneven and parallel to each other. In particular, the central layer each layer 3 ₁ of the stack of 3 components, 3 _2, ..., 3 in the _k, at least locally, the contact surfaces S _0, S _1, ..., measured at right angles to S _k constant thickness e3 _1, e3 ₂ being, ..., there is e3 _k.

として規定される。 As shown in FIG. 1, the unevenness of each contact surface S ₀ , S ₁ or S ₀ , S ₁ ,..., S _k of the layered member 1 is recessed or protruded with respect to the general surface π of the contact surface. Formed by a plurality of features. Preferably, the average height of the features of the respective uneven contact surfaces S ₀ , S ₁ or S ₀ , S ₁ ,..., S _k is between 1 micrometer and 1 millimeter. The average height of each uneven contact surface feature is the arithmetic average using the distance y _i measured between the peak and surface π for each feature of the surface, as schematically shown in FIG.

Is defined as

According to one aspect of the present invention, the thickness e3 or e3 ₁ , e3 ₂ ,..., E3 _k of each constituent layer of the central layer 3 is determined by the uneven contact surfaces S ₀ , S of the layered member 1. ₁ or thinner than the average height of the features of S ₀ , S ₁ ,... S _k . This condition is important to increase the probability that the entrance interface of radiation into the layer of the central layer 3 and the exit interface of radiation from this layer will be parallel, so that the radiation through the layered member 1 Increase the percentage of specular transmission. Due to the visibility of the various layers, this condition is not strictly considered in FIGS.

Preferably, the thickness e3 or e3 ₁ , e3 ₂ ,..., E3 _k of each constituent layer of the central layer 3 is less than ¼ of the average height of the features of each uneven surface of the layered member It is. Practice, when the center layer 3 is a stack of thin layers or thin layer, the thickness of each of the layers e3 or e3 _1, e3 ₂ of the center layer 3, ..., e3 _k is a respective uneven laminar member It is about 1/10 or less than the average height of the feature of the contact surface.

FIG. 1 illustrates the path of radiation, which is incident on a layered member 1 on the side of the outer layer 2. The incident light R _i reaches the outer layer 2 at a predetermined incident angle θ. As shown in FIG. 1, the incident light R _i reaches the contact surface S ₀ between the outer layer 2 and the central layer 3 by a metal surface or in the variant of FIG. 2 respectively of the outer layer 2 and the central layer 3. 3 and in the variant of FIG. 3 is reflected due to the difference in refractive index of this contact surface between the outer layer 2 and the layer 3 ₁ . Since the contact surface S ₀ is uneven, reflection occurs in a plurality of directions R _r . Therefore, the reflection of radiation by the layered member 1 is diffused.

Some of the incident radiation is also refracted in the central layer 3. In the variant of FIG. 2, the contact surfaces S ₀ and S ₁ are parallel to each other, and according to Snell-Cartesian law, n2. sin (θ) = n4. imply sin (θ ′), where θ is the incident angle of radiation of the central layer 3 starting from the outer layer 2 and θ ′ is the refraction angle of radiation of the outer layer 4 starting from the central layer 3. . In the variant of FIG. 3, the contact surfaces S ₀ , S ₁ ,..., S _k are all parallel to each other, so that the relation n2. sin (θ) = n4. sin (θ ′) remains proven. Thus, in the two variations, the two refractive indices n2 and n4 of the outer layer, since substantially equal to each other, light rays R _t transmitted by laminar member is transmitted angle equal to their angle of incidence θ of the laminar member Transmitted at θ ′. Therefore, the transmission of radiation by the layered member 1 is regular transmission.

  In a similar manner, in the two variants, radiation incident on the layered member 1 on the side of the outer layer 4 is reflected by the layered member in a diffusing manner and transmitted in a specular transmission manner for the same reason as before.

  Advantageously, the layered member 1 includes an anti-reflective coating 6 on at least one of its flat outer surfaces 2A and 4A. Preferably, an antireflective coating 6 is provided on each outer major surface of the layered member intended to receive radiation. In the embodiment of FIG. 1, the antireflection coating 6 is provided only on the surface 2 </ b> A of the outer layer 2 because this is the surface of the layered member that is directed to the radiation incident side.

  As already mentioned, the antireflective coating 6 provided on the flat surface 2A and / or 4A of the outer layer 2 or 4 is of any type that can reduce the reflection of radiation at the interface between the atmosphere and the outer layer. It's okay. It can in particular be a layer having a refractive index between the refractive index of the atmosphere and the refractive index of the outer layer, a stack of thin layers functioning as an interference filter, or a stack of thin layers having a refractive index gradient.

  An example of a method for producing the layered member 1 is described below with reference to FIGS.

  In the case illustrated in FIG. 4, the outer layers 2 and 4 of the layered member 1 are formed by two soft transparent substrates having substantially the same refractive index. Each substrate 2 or 4 has a flat main surface 2A or 4A and an uneven main surface 2B or 4B. The irregularities of the substrates 2 and 4 are complementary to each other so that the substrates can be nested within each other in a contact manner by engagement of those irregularities.

  The substrates 2 and 4 can in particular be two identical substrates made of uneven glass of the SATINOVO®, ALBARINO® or MASTERCLASS® type. As a variant, at least one of the two substrates 2 and 4 can be a rigid substrate based on, for example, polymethyl methacrylate or a polymer material of the polycarbonate type.

  The central layer 3 is formed by an adhesive layer made of a transparent polymer having a refractive index different from that of the substrates 2 and 4. As schematically shown in FIG. 4, the production of the layered member involves placing a central layer 3 between the uneven surfaces 2B and 4B of the substrates 2 and 4, and these surfaces 2B and 4B. Are arranged in advance facing each other in a three-dimensional arrangement in which their irregularities are strictly parallel to each other.

  The relative position of the uneven surfaces 2B and 4B, including their features parallel to each other, in particular by starting from the nested configuration of the substrates 2 and 4 with their unevenness in contact with each other and It can be obtained by moving one of the substrates away from the other substrate by translation along an axis perpendicular to the central plane of the substrate.

  As an example, when the substrates 2 and 4 are made of glass, the central layer 3 may be a layer of adhesive having a refractive index different from that of glass. This adhesive may initially be in a paste state. In this case, the method for producing the layered member 1 includes a step in which the thickness of the adhesive in the paste state is applied to one uneven surface of the two substrates 2 or 4, and then the unevenness thereof. Can include a step in which the thickness of the adhesive is compressed between the uneven surfaces 2B and 4B which are arranged parallel to each other.

  The compression of the adhesive thickness between the uneven surfaces 2B and 4B is indicated by the arrow F in FIG. 4 so that the adhesive is filled to the depths of the uneven surfaces 2B and 4B. Thus, the relative movement of the substrates 2 and 4 in the direction of each other is performed. In a subsequent step, the adhesive hardens between the uneven surfaces 2B and 4B so that the bases 2 and 4 are firmly bonded together by the layer of adhesive forming the central layer 3.

  Along the axis perpendicular to the central plane of the substrate, in order to compress the adhesive layer, while maintaining the position of the substrates 2 and 4 with their uneven surfaces facing each other with their unevenness parallel to each other It may be advantageous to use a device with means for translating one substrate relative to the other. Such a device is in particular in the direction of two opposite plates, intended to receive one flat surface of each of the two substrates, so that the uneven surfaces of the substrates face each other. A system for translating the plate may be included.

  The method illustrated in FIGS. 5 and 6 is different from the method of FIG. 4 in that the center layer 3 is deposited along the uneven surface 2B of the hard or soft transparent substrate that forms the outer layer 2 of the layered member 1. Is different. The main surface 2A of the substrate on the opposite side of the uneven surface 2B is flat. This substrate 2 can in particular be a substrate made of rugged glass of the SATINOVO®, ALBARINO® or MASTERCLASS® type. As a variant, the substrate 2 can be a substrate based on a hard or soft polymer material.

Regardless of whether it is a single layer or formed by stacking multiple layers, the conformal deposition of the central layer 3 is performed in particular by magnetron sputtering under vacuum. With this technique, a single layer can be deposited along the roughened surface 2B of the substrate 2, or various layers of the stack can be continuously deposited along the roughened surface 2B of the substrate 2. It becomes possible. In particular, these are dielectric thin layers, in particular layers of Si ₃ N ₄ , SnO ₂ , ZnO, SnZnO _x , AlN, NbO, NbN, TiO ₂ , SiO ₂ , Al ₂ O ₃ , MgF ₂ , AlF ₃ . Or a thin metal layer, in particular silver, gold, titanium, niobium, silicon, aluminum, a nickel-chromium (NiCr) alloy, or a layer of an alloy of these metals.

In the method of FIG. 5, the second outer layer 4 of the layered member 1 is transparent having a refractive index substantially equal to that of the substrate 2 (which is initially in a viscous state suitable for the molding operation and is curable). It is formed by covering the central layer 3 with layers. In a viscous state, this layer is adapted to the unevenness of the surface 3B of the central layer 3 on the opposite side of the substrate 2. Therefore, in the cured state of the layer 4, the contact surface S ₁ between the center layer 3 and the outer layer 4 is sufficiently uneven and parallel to the contact surface S ₀ between the center layer 3 and the outer layer 2. To ensure that.

  The layer 4 can be a layer of photocrosslinkable and / or photopolymerizable material that is initially deposited in liquid form and then deposited on the uneven surface 3B of the central layer 3 that is cured by irradiation, in particular UV irradiation. As a variant, the layer 4 may be a sol-gel type layer. Especially when the substrate 2 is made of glass, it can be silica glass deposited on the uneven surface 3B of the central layer 3 by a sol-gel method.

In the method of FIG. 6, the second outer layer 4 of the layered member 1 is formed from the central layer 3 of the transparent polymer laminated intermediate layer 4 ₁ and the transparent substrate 4 ₂ both having substantially the same refractive index as that of the substrate _2. Formed by superposition starting. If the substrate 2 is made of glass, the second outer layer 4 is a laminate made of PVB or EVA, for example, arranged against the uneven surface 3B of the central layer 3 opposite to the substrate 2 The intermediate layer 4 ₁ can be formed by superimposing the glass substrate 4 ₂ on the intermediate layer 4 ₁ .

In this case, the outer layer 4 is bonded to the substrate 2 that is previously covered with the central layer 3 by a conventional lamination method. In this method, the polymer laminated intermediate layer 4 ₁ and the substrate 4 ₂ are arranged continuously, starting from the rough main surface 3B of the central layer 3, and then at least the polymer, for example by means of a press or oven. compression and / or heating of a laminated glass transition temperature of the intermediate layer 4 ₁ is added to the laminate structure, it thus being formed. During this lamination process, the intermediate layer 4 _1, is along the surface irregularities 3B with irregularities of the center layer 3, and it is sufficiently uneven contact surface S ₁ between the center layer 3 and the outer layer 4 And that it is parallel to the contact surface S ₀ between the center layer 3 and the outer layer 2.

In the method illustrated in FIG. 7, the layered member 1 is a soft film having a total thickness of about 200 to 300 μm. The outer layer 2 of this layered member is applied to the soft main film 2 ₁ made of a polymer material whose two main surfaces are flat, and one flat main surface of the film 2 _1. It is formed by a layer 2 ₂ superposition made of a material photocrosslinkable and / or photopolymerizable below.

As an example, film 2 ₁ is polyethylene terephthalate (PET) film having a thickness of 100 [mu] m, and the layer 2 ₂ of JSR Corporation Inc. KZ6661 type UV curable resin sold by having a thickness of about 10μm Is a layer. Film 2 ₁ and layer 2 ₂ have substantially the same refractive index of about 1.65 at 550 nm. In cured state, the resin layer 2 _2, have good adhesion to the PET.

Resin layer 2 ₂ is applied to the membrane 2 ₁ viscous to allow for unevenness formation to be introduced into the surface 2B of the film 2 ₁ opposite. As illustrated in FIG. 7, the surface ₂ </ b> B can be formed by using a roll 9 having unevenness complementary to that to be formed by the layer 22 on the surface. As soon as the irregularity is formed, the film 2 ₁ and the resin layer 2 ₂ superimposed, indicated by the arrows in FIG. 7, is irradiated with UV irradiation, and it is, the unevenness formed, and film 2 ₁ and the resin allowing the layer 2 ₂ of with the resin layer 2 ₂ solidification assembly.

Next, a central layer 3 having a refractive index different from that of the outer layer 2 is deposited along the uneven surface 2B by magnetron sputtering. As described above, the central layer may be a single layer or may be formed by stacking layers. For example, it may be a TiO ₂ layer having a thickness of about 50 nm and a refractive index of 2.45 at 550 nm.

  Next, a second PET film having a thickness of 100 μm is deposited on the central layer 3 to form the second outer layer 4 of the layered member 1. The second outer layer 4 is made to conform to the uneven surface 3B of the central layer 3 opposite to the outer layer 2 by compression and / or heating at the glass transition temperature of PET.

  An adhesive layer 7 covered with a protective strip (liner) 8 intended to be removed for bonding may be applied to either one of the outer surfaces 2A and 4A of the layered member 1. Thus, the layered member 1 is in the form of a soft film that can be readily applied by adhering to a surface such as a glazing surface, for example, to impart diffuse reflection properties to this surface. In the embodiment of FIG. 7, the adhesive layer 7 and the protective strip 8 are applied to the outer surface 4 A of the layer 4. An antireflection coating 6 is provided on the outer surface 2A of the layer 2 (for receiving incident radiation).

  Particularly advantageously, as shown in FIG. 7, the various steps of the method can be carried out continuously on one and the same production line.

  The introduction of the anti-reflective coating (s) 6 of the layered member 1 is not represented in FIGS. In each of the methods illustrated in these drawings, the anti-reflective coating (s) 6 can be introduced on the flat surface 2A and / or 4A of the outer layer, either before or after assembly of the layered member. It must be noted.

  The invention is not limited to the embodiments described or shown. In particular, as in the embodiment of FIG. 7, when the layered member is a soft film, the thickness of each outer layer formed on the basis of a polymer film, such as a PET film, can be more than 10 μm, especially about 10 μm to 1 mm. The thickness can be

Further, roughening of the first outer layer 2 of the embodiment of Figure 7, without the use of curable resin layer 2 ₂ deposited on the polymer film 2 _1, however, uses a role of particular uneven rolling by pressing using or a punch, it is possible to obtain by direct hot embossing of polymer films 2 _1.

  Further, in order to improve the adhesion of the layered member in the form of the soft film illustrated in FIG. 7, a polymer laminated intermediate layer can be inserted between the center layer 3 and the second polymer film 4, Here, this laminated intermediate layer has substantially the same refractive index as the films 2 and 4 forming the outer layer. In this case, in a manner similar to the embodiment of FIG. 6, the second outer layer is formed by superposition of the laminated intermediate layer and the second polymer film, which is the first coated beforehand with the central layer 3. Adhered to the outer layer 2 by conventional lamination methods (compression and / or heating at least at the glass transition temperature of the laminated interlayer of the polymer applied to the laminated structure).

The reflection characteristics of four examples of layered members according to the present invention are shown in Table 1 below. The reflection characteristics of the layered member shown in Table 1 are as follows.
T _L : Visible light transmission (%) measured according to standard ISO standard 9050: 2003 (light source D65, observer with 2 ° field of view).
Haze T: Transmission (in%) measured using a haze meter according to standard ASTM D1003 for radiation incident on the layered member on the side of the outer layer 2.
R _L : total light reflection in the visible range (in%) with respect to radiation incident on the layered member on the side of the outer layer 2 measured according to standard ISO standard 9050: 2003 (light source D65, observer with 2 ° field of view).
Haze R: Incident on the layered member on the side of the outer layer 2, defined as the ratio of total visible light reflection (% units) measured by Minolta portable machine divided by visible non-specular light reflection (% units) Haze in reflection with respect to radiating (in%).

  Regarding each of Examples 1 to 4 shown in Table 1, the base material used as the outer layer 2 has a thickness of 6 mm, and has an uneven Saint-Gobain obtained by acid treatment on one of its main surfaces. It is a SATINOVO (registered trademark) glass manufactured by Glass. The average height of the uneven features of the outer layer 2 (corresponding to the roughness Ra of the uneven surface of the SATINOVO (registered trademark) glass) is about 3 μm.

  Further, for each of Examples 1-4, the central layer 3 of the constituent layer (s) was deposited by magnetron sputtering on the uneven surface 2B of the outer layer 2 using the following deposition conditions:

  In Examples 1 to 3, the outer layer 4 was combined with a PLAILUX (registered trademark) glass manufactured by Saint-Gobain Glass having a thickness of 4 mm, and a resin NOA75 (registered trademark) manufactured by Norland Optics having a thickness of about 100 μm. Alternatively, it is formed by a NOA65 (registered trademark) layer. In each of Examples 1 to 3, the resin was deposited in a liquid state on the uneven surface 3B of the central layer 3 on the opposite side of the outer layer 2 so as to conform to the unevenness of the surface 3B, and then PLAILUX (registered) After being covered with glass, it was cured under the action of UV irradiation.

  In Example 4, the outer layer 4 is formed by an EVA laminated interlayer having a thickness of 0.4 mm combined with a PLAILUX® glass made by Saint-Gobain Glass having a thickness of 4 mm. The EVA intermediate layer was placed on the uneven surface 3B of the central layer 3 opposite the outer layer 2 and then covered with PLAILUX® glass. The resulting laminate structure is pressed and transferred into an oven at a temperature of 105 ° C., which allows assembly of the layered member and adaptation of the EVA intermediate layer to the irregularities of the surface 3B of the central layer 3 .

The results from Table 1 show that the following were obtained for each of Examples 1-4.
Good light transmission combined with low haze in transmission, ie good specular transmission through the layered member. Thus, according to the object of the present invention, the vision through the layered member is transparent. This property is confirmed visually for the transparent and non-translucent samples for the four examples.
High haze in reflection, ie a high ratio of diffuse reflection to total reflection in the layered member. Thus, according to the object of the invention, a “mirror” type reflection of the layered member is avoided.

The percentage of diffuse reflection relative to total reflection in the layered member can be adjusted by using several parameters of the layered member. In particular, this percentage can also be increased by introducing one or both of the following strategies:
An anti-reflective coating is provided that covers each outer surface of the layered member intended to receive incident radiation. Thereby, the specular reflection by this flat outer surface can be limited and thereby the uneven contact surface between adjacent layers of the layered member rather than the specular mode of reflection by the flat outer surface Makes it possible to show diffuse-style reflections.
Enhancing the refractive index gap at the contact surface between each outer layer of the layered member located on the incident side of radiation and the central layer, and / or each contact surface between adjacent layers of the central layer. This makes it possible to increase the reflection of radiation (which is diffuse reflection) at these contact surfaces.

Claims (21)

A transparent layered member (1) having two flat outer main surfaces (2A, 4A),
Two outer layers (2, 4) each comprising one of the two outer major surfaces (2A, 4A) of the layered member and composed of a dielectric material having substantially the same refractive index (n2, n4) And a central layer (3) inserted between the outer layers, which is formed by a single layer which is a dielectric layer or metal layer having a different refractive index (n3) from the outer layer or is different from the outer layer A central layer (3) formed by stacking layers (3 ₁ , 3 ₂ ,..., 3 _k ) comprising at least one dielectric layer or metal layer having a ratio
Each contact surface (S ₀ , S ₁₎ between two adjacent layers of a layered member, one of which is a dielectric layer and the other is a metal layer or two dielectric layers having different refractive indices. ₁ ,..., S _k ) is between two adjacent layers that are textured and one is a dielectric layer and the other is a metal layer or two dielectric layers with different refractive indices. A projection screen comprising a layered member (1), characterized in that it is parallel to the remaining uneven contact surface.   The absolute value of the difference in refractive index at 550 nm between the outer layer (2, 4) on the one hand and the at least one dielectric layer of the central layer (3) on the other hand is 0.3 or more, Item 4. The projection screen according to Item 1.   At least one of the two outer layers (2, 4) is a transparent substrate, one of the main surfaces (2B, 4B) of the transparent substrate is uneven, and the other main surface (2A, 4A) The projection screen according to claim 1, wherein the projection screen is flat.   The center layer (3) is formed by a layer of dielectric material having a different refractive index than the outer layer, and the outer layers (2, 4) are assembled by the center layer (3). 4. The projection screen according to any one of 3 above.   Projection screen according to any one of claims 1 to 3, characterized in that the constituent layer of the central layer (3) or each constituent layer is a layer deposited by sputtering on a rough surface. .   Projection screen according to any one of claims 1 to 3, characterized in that the central layer (3) comprises at least one dielectric thin layer and / or at least one metal thin layer.   The central layer (3) is a stack of transparent thin layers comprising an alternating arrangement (n ≧ 1) of n metal functional layers and (n + 1) antireflection coatings, each metal functional layer being 2 The projection screen according to claim 1, wherein the projection screen is deposited between the antireflection coatings. The projection screen according to claim 7, wherein the metal functional layer is a functional layer based on silver or a metal alloy containing silver. When the thickness of each layer of the central layer (3) is measured at right angles to the contact surface with the adjacent layer, 1 / of the average height of the uneven features on each contact surface with the adjacent layer The projection screen according to claim 1, wherein the projection screen is less than four.   An antireflection coating (6) is included at an interface between at least one of the outer main surfaces (2A, 4A) and the constituent material of the outer layer (2, 4) forming the outer main surface. The projection screen according to any one of claims 1 to 9.   The projection screen according to any one of claims 1 to 10, characterized in that the main surfaces (2A, 4A) on the outside of the layered member are parallel to each other. Of the two outer layers, the first outer layer (2) is a transparent substrate, one of the main surfaces (2B) of the transparent substrate is uneven, and the other main surface (2A) is flat. A dielectric layer having a refractive index different from that of the first outer layer (2), the central layer (3) being deposited along the roughened main surface (2B) of the first outer layer (2); Refraction different from the first outer layer (2) formed by a single layer which is a metal layer or continuously deposited along the roughened main surface (2B) of the first outer layer (2) 12. The method according to claim 1, characterized in that it is formed by stacking layers (3 ₁ , 3 ₂ ,..., 3 _k ) comprising at least one dielectric layer or metal layer having a ratio. The projection screen described.   The second outer layer (4) is initially deposited on the main surface (3B) with the irregularities of the central layer (3) opposite to the first outer layer (2) by making it into a viscous state suitable for the molding operation. 13. Projection screen according to claim 12, characterized in that it includes a layer having substantially the same refractive index as the first outer layer (2). The second outer layer (4) is substantially the same as the first outer layer (2), which is disposed on the main surface (3B) with irregularities of the central layer (3) opposite to the first outer layer (2). 13. Projection screen according to claim 12, characterized in that it comprises a laminated intermediate layer (4 ₁ ) of polymers having the same refractive index. As the outer layers (2, 4), a step of preparing two transparent base materials composed of dielectric materials having substantially the same refractive index, each of the transparent base materials being provided with unevenness Having a main surface (2B, 4B) and the other flat main surface (2A, 4A), the irregularities of the two transparent substrates are complementary to each other;
The central layer (3) including at least one dielectric layer or metal layer having a refractive index (n3) different from the refractive index (n2, n4) of the outer layer is disposed so as to face each other so that the unevenness is parallel to each other. A projection screen according to any one of claims 1 to 11, characterized in that it includes a step of placing it between the roughened main surfaces (2B, 4B) of two transparent substrates. Way for. Preparing a transparent base material with one main surface (2B) being uneven and the other main surface (2A) being flat as a first outer layer (2);
A dielectric layer having a refractive index different from that of the first outer layer (2), wherein the central layer (3) is deposited on the main surface (2B) having the irregularities of the first outer layer; When formed by a single layer which is a layer or a metal layer, it is carried out by depositing a central layer (3) along the rough main surface (2B), or the central layer (3) is a first layer. When formed by stacking layers (3 ₁ , 3 ₂ ,..., 3 _k ) including at least one dielectric or metal layer having a different refractive index from the outer layer (2) of A step performed by depositing the layers (3 ₁ , 3 ₂ ,..., 3 _k ) of the central layer (3) continuously along the surface (2B);
Forming a second outer layer (4) on the roughened main surface (3B) of the central layer (3) opposite to the first outer layer (2), the first outer layer (2) and the first outer layer (2) 15. Method for manufacturing a projection screen according to any one of claims 1 to 14, characterized in that the two outer layers (4) are composed of a dielectric material having substantially the same refractive index. . The center layer (3) is deposited along the roughened main surface (2B) of the first outer layer (2) by sputtering, in particular magnetron sputtering, or the layer (3 ₁ ) of the center layer (3). The method according to claim 16, characterized in that 3 ₂ , ..., 3 _k ) are continuously deposited along the roughened main surface (2B) of the first outer layer (2).   The second outer layer (4) has substantially the same refraction as that of the first outer layer (2) on the main surface (3B) provided with unevenness of the central layer (3) opposite to the first outer layer (2). 18. A method according to claim 16 or 17, characterized in that it is formed by depositing a layer having a rate and initially in a viscous state suitable for a molding operation.   The second outer layer (4) has a refractive index substantially the same as that of the first outer layer (2) on the main surface (3B) provided with unevenness of the central layer (3) on the opposite side to the first outer layer (2). Is formed by placing a layer based on a polymer material and then subjecting the layer based on the polymer material to the roughened main surface (3B) of the central layer (3) by compression and / or heating. 18. A method according to claim 16 or 17, characterized.   A display screen comprising the projection screen according to claim 1.   A glazing of a head-up display system comprising the projection screen according to claim 1.

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